PHOENIX - Police said an off-duty Border Patrol agent who allegedly fired a rifle at police responding to a 911 call made by a person reporting domestic violence in a Maricopa home was found dead inside.

Maricopa Police Department spokesman Ricardo Alvarado said one officer returned fire but that it wasn't immediately known whether the man was killed by gunfire from police or himself.

Alvarado said a robot sent inside the home by an Arizona Department of Public Safety SWAT team that used explosives to breach the front door later found the man's body in an upstairs closet.

Alvarado identified the man as Jeremy Russo, 40, who was employed as a Border Patrol agent, Alvarado said.

The U.S. Customs and Border Protection officials released a statement that described Russo's death as an "apparent suicide."

Russo joined the Border Patrol in September 2011 and served as an agent at the Casa Grande Border Patrol Station, the statement said.

The robot was sent in about 1 a.m., hours after the incident began Monday evening.

According to Alvarado, the man's wife and his two children had earlier made it out of the home unharmed. No officers were injured during the exchange of gunfire, Alvarado said.

Alvarado said police recovered an AR-15-style rifle from the scene. As part of the investigation, police expect to interview the officer who exchanged fire with the suspect.